Transmissions include, among other components, a clutch assembly. The interposition of the clutch assembly between a drive shaft and a driven shaft permits the drive shaft, connected to a motor or an engine, to be coupled, releasably, to the driven shaft. This coupling through the clutch assembly may cause the driven shaft to rotate at the same rate as the drive shaft. It may also enable a driven shaft to rotate at a different rotation rate as the drive shaft, or be completely decoupled from the driven shaft.
One component of the clutch assembly that enables the releasable coupling of the drive shaft to the driven shaft is a stack of friction elements interleaved with steel plates. This interleaved stack can transfer torque from the drive shaft to the driven shaft, or it can be decoupled from one of the shafts, thereby preventing the transfer of torque. Given this arrangement, a clutch assembly is limited in the amount of torque that it can transfer from the driven shaft to the drive shaft in part by the torque that the interleaved stack can withstand: When an upper torque limit is exceeded, the interleaved disks can slip with respect to one another, allowing the clutch to slip excessively, degrading performance and increasing wear.